Interest in how Microsoft would deploy an extension of the .NET Framework called Dublin in the cloud exceeded anyone's expectations today, as thousands of attendees literally spilled over into a spare room to watch the first Dublin demos on video.

Dublin is, as was already known prior to today, Microsoft's platform for extending .NET services as distributed architecture; but now we know that Dublin will be used for deploying custom .NET applications on Windows Azure. This afternoon, the company's Jacob Avital and Mauricio Ordonez performed live demonstrations of how a cloud-based .NET would asynchronously capture customer-generated events over the Web, respond to those events with code, and report on the results.

Besides the new extension to .NET itself, this system utilizes some basically familiar tools: the existing Visual Studio, Windows Communication Foundation (WCF), and Workflow Foundation (WF).

BETA CAPSULE Dublin

The current codename for the Windows Applications Server extension project which is the company's platform for distributing .NET applications in the cloud.

Microsoft's objective is to leverage its existing investment in the .NET Framework so that businesses can readily deploy applications, using the tools and resources they already own (including Visual Studio), on a cloud computing platform such as Windows Azure.

Dublin architecture asks developers to build "event handlers," borrowing a phraseology from another era of Windows programming, except that these events are generated by Web users, not by the end user of a GUI. These events are then handled through "virtual ports" that capture and interpret the events asynchronously, and then respond. While conceivably Dublin could deploy an existing .NET application to the cloud, you'd lose the point. Truly distributed applications respond to events that have been "published," and to which customers "subscribe" -- a signal which the application can recognize and accept. Using tools such as Workflow Foundation (WF), developers can build .NET code that responds to published events through what's called a service bus in Windows Communication Foundation. (This is the technology which Microsoft engineers predicted in 2004 would have already rendered IIS obsolete by now.) The result is an asynchronously behaving component that can be deployed as a component in a distributed composite application.

It is classic Microsoft to leverage its strengths in one area to build in another. It absolutely differentiates Microsoft's approach to cloud computing from its competitors in that it enables customers to build their own services to be deployed in the cloud, rather than 1) float an image of Windows Server in the cloud and pretend it's on-site; or 2) try to adapt someone else's cloud-based "out-of-the-cloud" application to suit their own purposes explicitly.

10:30 am EST November 6, 2008 - A Microsoft spokesperson contacted BetaNews expressing the company's concern that the way we presented this story and capsule on Dublin technology might make it appear to readers that the Dublin platform was the .NET Services platform for Windows Azure.

This certainly was not the impression we meant to give; Microsoft has made it clear that Dublin is a technology for extending so-called composite applications to the company's cloud platform, though it is not Azure nor is it a component of Azure directly. Whatever Dublin ends up being called, it will be packaged separately. Meanwhile, .NET Services extends the .NET Framework into the realm of Azure, and Dublin makes it possible for composite applications written around the framework to be extended to .NET Services.

My personal feeling is that the original story made that pretty clear, but just in case it didn't, there's the restatement for you.

In the near future, BetaNews will be presenting our complete interview with Burley Kawasaki, the director of product management in charge of Dublin, who will go into much further detail about the architecture and Microsoft's plans for marketing it.